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Diffstat (limited to 'libAACenc/src/band_nrg.cpp')
| -rw-r--r-- | libAACenc/src/band_nrg.cpp | 297 |
1 files changed, 297 insertions, 0 deletions
diff --git a/libAACenc/src/band_nrg.cpp b/libAACenc/src/band_nrg.cpp new file mode 100644 index 0000000..8ae271b --- /dev/null +++ b/libAACenc/src/band_nrg.cpp @@ -0,0 +1,297 @@ +/***************************** MPEG-4 AAC Encoder ************************** + + (C) Copyright Fraunhofer IIS (1999) + All Rights Reserved + + Please be advised that this software and/or program delivery is + Confidential Information of Fraunhofer and subject to and covered by the + + Fraunhofer IIS Software Evaluation Agreement + between Google Inc. and Fraunhofer + effective and in full force since March 1, 2012. + + You may use this software and/or program only under the terms and + conditions described in the above mentioned Fraunhofer IIS Software + Evaluation Agreement. Any other and/or further use requires a separate agreement. + + + $Id$ + Initial author: M. Werner + contents/description: Band/Line energy calculations + + This software and/or program is protected by copyright law and international + treaties. Any reproduction or distribution of this software and/or program, + or any portion of it, may result in severe civil and criminal penalties, and + will be prosecuted to the maximum extent possible under law. + +******************************************************************************/ + +#include "band_nrg.h" + + +/***************************************************************************** + functionname: FDKaacEnc_CalcSfbMaxScaleSpec + description: + input: + output: +*****************************************************************************/ +void +FDKaacEnc_CalcSfbMaxScaleSpec(const FIXP_DBL *RESTRICT mdctSpectrum, + const INT *RESTRICT bandOffset, + INT *RESTRICT sfbMaxScaleSpec, + const INT numBands) +{ + INT i,j; + FIXP_DBL maxSpc, tmp; + + for(i=0; i<numBands; i++) { + maxSpc = (FIXP_DBL)0; + for (j=bandOffset[i]; j<bandOffset[i+1]; j++) { + tmp = fixp_abs(mdctSpectrum[j]); + maxSpc = fixMax(maxSpc, tmp); + } + sfbMaxScaleSpec[i] = (maxSpc==(FIXP_DBL)0) ? (DFRACT_BITS-2) : CntLeadingZeros(maxSpc)-1; + /* CountLeadingBits() is not necessary here since test value is always > 0 */ + } +} + +/***************************************************************************** + functionname: FDKaacEnc_CheckBandEnergyOptim + description: + input: + output: +*****************************************************************************/ +FIXP_DBL +FDKaacEnc_CheckBandEnergyOptim(const FIXP_DBL *RESTRICT mdctSpectrum, + INT *RESTRICT sfbMaxScaleSpec, + const INT *RESTRICT bandOffset, + const INT numBands, + FIXP_DBL *RESTRICT bandEnergy, + FIXP_DBL *RESTRICT bandEnergyLdData, + INT minSpecShift) +{ + INT i, j, scale, nr = 0; + FIXP_DBL maxNrgLd = FL2FXCONST_DBL(-1.0f); + FIXP_DBL maxNrg = 0; + FIXP_DBL spec; + + for(i=0; i<numBands; i++) { + scale = fixMax(0, sfbMaxScaleSpec[i]-4); + FIXP_DBL tmp = 0; + for (j=bandOffset[i]; j<bandOffset[i+1]; j++){ + spec = mdctSpectrum[j]<<scale; + tmp = fPow2AddDiv2(tmp, spec); + } + bandEnergy[i] = tmp<<1; + + /* calculate ld of bandNrg, subtract scaling */ + bandEnergyLdData[i] = CalcLdData(bandEnergy[i]); + if (bandEnergyLdData[i] != FL2FXCONST_DBL(-1.0f)) { + bandEnergyLdData[i] -= scale*FL2FXCONST_DBL(2.0/64); + } + /* find index of maxNrg */ + if (bandEnergyLdData[i] > maxNrgLd) { + maxNrgLd = bandEnergyLdData[i]; + nr = i; + } + } + + /* return unscaled maxNrg*/ + scale = fixMax(0,sfbMaxScaleSpec[nr]-4); + scale = fixMax(2*(minSpecShift-scale),-(DFRACT_BITS-1)); + + maxNrg = scaleValue(bandEnergy[nr], scale); + + return maxNrg; +} + +/***************************************************************************** + functionname: FDKaacEnc_CalcBandEnergyOptimLong + description: + input: + output: +*****************************************************************************/ +INT +FDKaacEnc_CalcBandEnergyOptimLong(const FIXP_DBL *RESTRICT mdctSpectrum, + INT *RESTRICT sfbMaxScaleSpec, + const INT *RESTRICT bandOffset, + const INT numBands, + FIXP_DBL *RESTRICT bandEnergy, + FIXP_DBL *RESTRICT bandEnergyLdData) +{ + INT i, j, shiftBits = 0; + FIXP_DBL maxNrgLd = FL2FXCONST_DBL(0.0f); + + FIXP_DBL spec; + + for(i=0; i<numBands; i++) { + INT leadingBits = sfbMaxScaleSpec[i]-4; /* max sfbWidth = 96 ; 2^7=128 => 7/2 = 4 (spc*spc) */ + FIXP_DBL tmp = FL2FXCONST_DBL(0.0); + /* don't use scaleValue() here, it increases workload quite sufficiently... */ + if (leadingBits>=0) { + for (j=bandOffset[i];j<bandOffset[i+1];j++) { + spec = mdctSpectrum[j]<<leadingBits; + tmp = fPow2AddDiv2(tmp, spec); + } + } else { + INT shift = -leadingBits; + for (j=bandOffset[i];j<bandOffset[i+1];j++){ + spec = mdctSpectrum[j]>>shift; + tmp = fPow2AddDiv2(tmp, spec); + } + } + bandEnergy[i] = tmp<<1; + } + + /* calculate ld of bandNrg, subtract scaling */ + LdDataVector(bandEnergy, bandEnergyLdData, numBands); + for(i=numBands; i--!=0; ) { + FIXP_DBL scaleDiff = (sfbMaxScaleSpec[i]-4)*FL2FXCONST_DBL(2.0/64); + + bandEnergyLdData[i] = (bandEnergyLdData[i] >= ((FL2FXCONST_DBL(-1.f)>>1) + (scaleDiff>>1))) + ? bandEnergyLdData[i]-scaleDiff : FL2FXCONST_DBL(-1.f); + /* find maxNrgLd */ + maxNrgLd = fixMax(maxNrgLd, bandEnergyLdData[i]); + } + + if (maxNrgLd<=(FIXP_DBL)0) + { + for(i=numBands; i--!=0; ) + { + INT scale = fixMin((sfbMaxScaleSpec[i]-4)<<1,(DFRACT_BITS-1)); + bandEnergy[i] = scaleValue(bandEnergy[i], -scale); + } + return 0; + } + else + { /* scale down NRGs */ + while (maxNrgLd>FL2FXCONST_DBL(0.0f)) + { + maxNrgLd -= FL2FXCONST_DBL(2.0/64); + shiftBits++; + } + for(i=numBands; i--!=0; ) + { + INT scale = fixMin( ((sfbMaxScaleSpec[i]-4)+shiftBits)<<1, (DFRACT_BITS-1)); + bandEnergyLdData[i] -= shiftBits*FL2FXCONST_DBL(2.0/64); + bandEnergy[i] = scaleValue(bandEnergy[i], -scale); + } + return shiftBits; + } +} + + +/***************************************************************************** + functionname: FDKaacEnc_CalcBandEnergyOptimShort + description: + input: + output: +*****************************************************************************/ +void +FDKaacEnc_CalcBandEnergyOptimShort(const FIXP_DBL *RESTRICT mdctSpectrum, + INT *RESTRICT sfbMaxScaleSpec, + const INT *RESTRICT bandOffset, + const INT numBands, + FIXP_DBL *RESTRICT bandEnergy) +{ + INT i, j; + + for(i=0; i<numBands; i++) + { + int leadingBits = fixMax(0,sfbMaxScaleSpec[i]-4); /* max sfbWidth = 96 ; 2^7=128 => 7/2 = 4 (spc*spc) */ + FIXP_DBL tmp = FL2FXCONST_DBL(0.0); + for (j=bandOffset[i];j<bandOffset[i+1];j++) + { + FIXP_DBL spec = mdctSpectrum[j]<<leadingBits; + tmp = fPow2AddDiv2(tmp, spec); + } + bandEnergy[i] = tmp<<1; + } + + for(i=0; i<numBands; i++) + { + INT scale = 2*fixMax(0,sfbMaxScaleSpec[i]-4); /* max sfbWidth = 96 ; 2^7=128 => 7/2 = 4 (spc*spc) */ + scale = fixMin(scale,(DFRACT_BITS-1)); + bandEnergy[i] >>= scale; + } +} + + +/***************************************************************************** + functionname: FDKaacEnc_CalcBandNrgMSOpt + description: + input: + output: +*****************************************************************************/ +void FDKaacEnc_CalcBandNrgMSOpt(const FIXP_DBL *RESTRICT mdctSpectrumLeft, + const FIXP_DBL *RESTRICT mdctSpectrumRight, + INT *RESTRICT sfbMaxScaleSpecLeft, + INT *RESTRICT sfbMaxScaleSpecRight, + const INT *RESTRICT bandOffset, + const INT numBands, + FIXP_DBL *RESTRICT bandEnergyMid, + FIXP_DBL *RESTRICT bandEnergySide, + INT calcLdData, + FIXP_DBL *RESTRICT bandEnergyMidLdData, + FIXP_DBL *RESTRICT bandEnergySideLdData) +{ + INT i, j, minScale; + FIXP_DBL NrgMid, NrgSide, specm, specs; + + for (i=0; i<numBands; i++) { + + NrgMid = NrgSide = FL2FXCONST_DBL(0.0); + minScale = fixMin(sfbMaxScaleSpecLeft[i], sfbMaxScaleSpecRight[i])-4; + minScale = fixMax(0, minScale); + + if (minScale > 0) { + for (j=bandOffset[i];j<bandOffset[i+1];j++) { + FIXP_DBL specL = mdctSpectrumLeft[j]<<(minScale-1); + FIXP_DBL specR = mdctSpectrumRight[j]<<(minScale-1); + specm = specL + specR; + specs = specL - specR; + NrgMid = fPow2AddDiv2(NrgMid, specm); + NrgSide = fPow2AddDiv2(NrgSide, specs); + } + } else { + for (j=bandOffset[i];j<bandOffset[i+1];j++) { + FIXP_DBL specL = mdctSpectrumLeft[j]>>1; + FIXP_DBL specR = mdctSpectrumRight[j]>>1; + specm = specL + specR; + specs = specL - specR; + NrgMid = fPow2AddDiv2(NrgMid, specm); + NrgSide = fPow2AddDiv2(NrgSide, specs); + } + } + bandEnergyMid[i] = NrgMid<<1; + bandEnergySide[i] = NrgSide<<1; + } + + if(calcLdData) { + LdDataVector(bandEnergyMid, bandEnergyMidLdData, numBands); + LdDataVector(bandEnergySide, bandEnergySideLdData, numBands); + } + + for (i=0; i<numBands; i++) + { + INT minScale = fixMin(sfbMaxScaleSpecLeft[i], sfbMaxScaleSpecRight[i]); + INT scale = fixMax(0, 2*(minScale-4)); + + if (calcLdData) + { + /* using the minimal scaling of left and right channel can cause very small energies; + check ldNrg before subtract scaling multiplication: fract*INT we don't need fMult */ + + int minus = scale*FL2FXCONST_DBL(1.0/64); + + if (bandEnergyMidLdData[i] != FL2FXCONST_DBL(-1.0f)) + bandEnergyMidLdData[i] -= minus; + + if (bandEnergySideLdData[i] != FL2FXCONST_DBL(-1.0f)) + bandEnergySideLdData[i] -= minus; + } + scale = fixMin(scale, (DFRACT_BITS-1)); + bandEnergyMid[i] >>= scale; + bandEnergySide[i] >>= scale; + } +} |